1. Field of the Invention
The present invention relates to a method for providing Quality of Service (QoS) through session classification in an Internet protocol version 6 (IPv6) network, and more particularly, to a method for classifying sessions created between terminals or nodes and providing specialized QoS for each session in providing multimedia network service in an IPv6 network.
2. Description of the Related Art
A session in an Internet protocol (IP) network can be defined in various ways according to the fields that the identification method is considering in. However, generally a session is defined using the information of a network layer such as an IP address and the information of a transmission layer such as a transmission control protocol/user datagram protocol (TCP/UDP) port information.
For example, a session in an IPv4 network is defined using source IPv4 address, destination IPv4 address, protocol number, source TCP/UDP port number, and destination TCP/UDP port number. Similarly, a session in an IPv6 network can be defined using source IPv6 address, destination IPv6 address, next header, source TCP/UDP port number, and destination TCP/UDP port number.
Transmission layer information (a source TCP/UDP port number and a destination TCP/UDP port number) contained in an IPv6 packet exists in the form of an extension header according to the header type defined by a standard. When there are a plurality of extension headers, the transmission layer information is located at an endmost portion of each extension header. Therefore, when a plurality of extension headers exist in an IPv6 packet, there is difficulty in extracting transmission layer information in high-speed networks.
Therefore, when the beginning of an extension header of an IPv6 packet is not transmission layer header such as TCP or UDP ports. In this case, since QoS is provided to a thick session grouping sessions whose source IPv6 address, destination IPv6 address and next header are same, a specialized control cannot be performed for each 5-tuple session. In addition, when a payload is encrypted just as an encapsulating security payload exists in an IPv6 packet, transmission layer information cannot be extracted unless each node performs decoding.